Aquarium Fertilizer Calculator

Planted tank fertilizer calculator: enter your tank volume in liters or gallons and see how much to dose, in grams for EI dry salts or mL for liquid fertilizers, per dose and per week. For example, a 60 L tank on the EI standard preset takes 2.45 g of KNO3 a week, about 0.82 g per dose at 3 doses a week.

Log doses, water changes and water tests, follow them on charts and get a reminder for the next dose. Pro, a one-time purchase, adds backup with photos, a tank report PDF, CSV files and livestock notes.

CALCULATE
• Liquid fertilizers: pick a product and get the dose for your tank from the label dose. Popular products from Seachem, Tropica, ADA, NilocG, Aquarium Co-op, Dennerle, JBL, UNS and more.
• Your own fertilizer: enter the label dose (mL per L) and it scales to your tank.
• EI dry salts: KNO3, KH2PO4, K2SO4 and CSM+B, with weekly ppm targets, grams per dose, teaspoon hints and a stock solution mode. Potassium from KNO3 and KH2PO4 is counted, so K2SO4 only tops up the rest.
• Presets: EI standard, EI low-tech and PPS-Pro. Every target can be changed.
• CO2 estimate from pH and KH, filled in from your latest water test.

LOG AND TRACK
• Several tanks, each with its own records.
• Water tests: pH, GH, KH, NO3, PO4 and temperature.
• Trend charts with doses and water changes marked.
• Tank check: a gentle hint from your NO3 readings when nitrate is building up or running low.
• Growth album with dated photos, easy to share.
• Dosing reminders at the interval you choose.
• Guide: what each nutrient does and signs of a deficiency.
• Copy your records as CSV at any time.
• Works offline. No account, no sign-up.

PRO (one-time purchase)
• Backup & restore: tanks, logs, your fertilizers, settings and album photos in one file, for a new phone.
• Tank report PDF for the period you choose: water test charts, doses and water changes, fertilizer totals and livestock notes.
• Save your records as a CSV file.
• Livestock & plant notes per tank: name, count, date added.
• No ads.
Calculating and logging stay free, with no usage limits.

FAQ
How much KNO3 for EI in a 60 L tank?
On the EI standard preset (25 ppm NO3 a week): 2.45 g a week, about 0.82 g per dose at 3 doses a week.

How much liquid fertilizer should I add?
Pick your product and enter your tank volume. A label dose of 5 mL per 250 L becomes 2 mL for a 100 L tank.

Does it work for a low-tech tank without CO2?
Yes. Use the EI low-tech or PPS-Pro preset, or your liquid fertilizer's dose.

Can I move my records and photos to a new phone?
Yes, with Pro backup & restore.

LIMITATIONS
• Doses are estimates from label doses and standard formulas, not a guarantee of results. Read the product label and test your water.
• For some products the doses per week are a general guideline, as the label does not state them.
• Teaspoon amounts are approximate. For small amounts, use a scale.
• The CO2 estimate reads high when soil, driftwood or pH products lower the pH.
• For planted aquariums only. Not for medical or veterinary use.
• Records and photos stay on your device. Use Pro backup to move them.
• Pro is purchased in the Android app through Google Play.

Product and brand names are trademarks of their owners. This app is independent and not affiliated with any manufacturer.

Recent changes:
Added more languages. Improved display and stability.